Extreme oxygen deprivation is central to the pathology of several diseases involving cardiac or pulmonary dysfunction. Oxygen deprivation also plays a role in the resistance of solid tumors to radiation or chemotherapy treatment. Understanding the genetic and cellular response oxygen-deprivation resistant organisms have to anoxia or hypoxia will facilitate the development of treatment for the rescue of damaged ischemic tissue or the destruction of oxygen deprived tumor cells. The long-term research goal is to identify and characterize the molecular mechanisms Caenorhabditis elegans use to survive oxygen deprivation. [unreadable] [unreadable] The objectives of this application are to characterize the cellular response nematodes have to oxygen deprivation and to identify genes required for oxygen deprivation survival. The central hypothesis of this application is that nematodes have developmentally dependent genetic and cellular mechanisms to survive oxygen deprivation. That is, a genetic mechanism that allows embryos to survive anoxia may not be important for the nematode adult to survive anoxia. We will use a combination of genetic, cell biological, and morphological studies to study oxygen deprivation in C. elegans. Pursuing the following specific aims will test the hypothesis of this application: [unreadable] [unreadable] Aim 1. Determine the role ODS-1 has in anoxic embryos. ODS-1 (Oxygen Deprivation Sensitive) was identified by a RNA interference (RNAi) screen for genes that are essential for C. elegans embryos to survive anoxia. The protein localization and phenotypic analysis of ODS-1 will be examined to understand the role this protein has in anoxia. [unreadable] [unreadable] Aim 2. Identify genes required for embryos to survive oxygen deprivation. A systematic RNAi screen will be used to identify genes required for embryos to survive anoxia or hypoxia. The phenotype of genes identified in this screen will be examined. [unreadable] [unreadable] Aim 3. Characterize the cellular response post-embryonic nematodes have to oxygen deprivation and identify genes required for post-embryonic nematodes to survive oxygen deprivation. To characterize the response post-embryonic wild type nematodes have to oxygen deprivation we will analyze tissues using Nomarski differential-interference contrast optical microscopy and visualization of green fluorescent protein in specific tissues. We will use systematic RNAi screen to identify genes required for post-embryonic nematodes to survive anoxia or hypoxia. [unreadable] [unreadable]